I stayed there from July 22 - 27 and it was the perfect choice! Very good location, if you take the Tohu subway line, the hotel is just 3 doors away.
Hotel staff spoke very good English. They gave fantastic advice on local tours and also helped to book the tours. They also gave great advice and provided time schedules for bus transport to the airport. The bus stop is only across the road, less than 5 mins walk so it was a blessing not having to drag my big luggage down to the subway station.
In room wifi didn't work and I had to go back to the reception twice to get the router. However, the staff was really polite and kept apologizing for this. The wifi worked perfectly after installing the router.
Air condition inside the room worked perfectly and the size of the room was also quite decent.
Only complaint was the pillows.. I was given 4 pillows but they were either too soft or too hard.
I would definitely go back to this hotel again.. All in all, great locations, plenty of good restaurants and shopping.

We stayed in the Mercure for 5 nights on our recent Sapporo trip. It is about 20 minutes walk from the JR station, but this can be done completely underground following subways and shopping concorses.

We paid about $US130 per night for our room on average, which was a bargain. Our room was sizeable by Japanese standards and was delightfully fitted out, including the impressive bathroom. The staff were very helpful and friendly and spoke generally excellent English. There was free room internet (both cable and wifi), with each room apparently having it's own dedicated wi-fi.

All in all a great stay, an excellent hotel. There are a wealth of dining options nearby, and I would highly recommend Kuro Shima, which is on B1 of the M-Square building next door. See my seperate review of Kuro Shima for more details.